The 2002 Au Sable Forks earthquake was an unusual and rare earthquake that struck North Country in 20 April, 2002 at 06:50:45 local time. This earthquake had a

moment magnitude The moment magnitude scale (MMS; denoted explicitly with or Mw, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. It was defined in a 1979 pape ...

of 5.1 and a

Modified Mercalli Intensity The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

of VII (''Very strong''). There was damage near the epicenter however there were no injuries nor deaths. Shortly after, another earthquake measuring 3.7 struck the same area.

Geologic setting

This earthquake and its aftershocks are located on the northeastern side of the Adirondack massif, on the Champlain fault zone. This

fault zone In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

is characterized by north-south striking brittle faults. These faults include both normal, usually high angle, as well as thrust/reverse faults. While Grenville-age structure is mostly striking east to west and is generally quite complex, the hard structure in the Adirondack Mountains are influenced by regional

fracture zone A fracture zone is a linear feature on the ocean floor—often hundreds, even thousands of kilometers long—resulting from the action of offset mid-ocean ridge axis segments. They are a consequence of plate tectonics. Lithospheric plates on eit ...

s that are trending north-northeast. Some of these are traced for hundreds of kilometers across the entire Adirondack massif and they have a clear expression in the morphology. However they cannot generally be classified as faults because they have surprisingly little accumulated displacement.

Earthquake

The earthquake that occurred near the town of Au Sable Forks, NY, on the 20th of April 2002 was the largest earthquake to strike the region since

1988 File:1988 Events Collage.png, From left, clockwise: The oil platform Piper Alpha explodes and collapses in the North Sea, killing 165 workers; The USS Vincennes (CG-49) mistakenly shoots down Iran Air Flight 655; Australia celebrates its Australian ...

and the biggest to be observed on regional broadband station networks. The shaking was felt in a wide region from

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. This event had a north-south striking thrust (reverse) fault mechanism at a depth of 8.7 km, which is consistent with the trend of usual faulting in the area. There were 80 aftershocks recorded more than a year after the earthquake, which 3 of them had a magnitude of 3.0 or larger.

Impact

Substantial damage was caused to roads, bridges, chimneys and water mains in Clinton and

Essex Essex () is a county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the River Thames to the south, and G ...

counties. People also reported damage to homes like cracked walls and foundations, items knocked off shelves as well as broken windows. Despite the damages and the felt intensity, no one was injured or killed.

Response

On May 16, 2002, a disaster declaration was issued by the President

George W. Bush George Walker Bush (born July 6, 1946) is an American politician who served as the 43rd president of the United States from 2001 to 2009. A member of the Republican Party, Bush family, and son of the 41st president George H. W. Bush, he ...

for the Clinton, Essex,

Franklin Franklin may refer to: People * Franklin (given name) * Franklin (surname) * Franklin (class), a member of a historical English social class Places Australia * Franklin, Tasmania, a township * Division of Franklin, federal electoral d ...

Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...

Warren A warren is a network of wild rodent or lagomorph, typically rabbit burrows. Domestic warrens are artificial, enclosed establishment of animal husbandry dedicated to the raising of rabbits for meat and fur. The term evolved from the medieval Angl ...

, and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

counties.

References

External links